In freezing climates, snow and ice can cause a number of dangerous roadway conditions that can be both hazardous and inconvenient. These dangerous road conditions can lead to an increase in traffic accidents. A number of deicing or anti-icing strategies, including mechanical, chemical, and thermal methods, have been employed to mitigate the effects of snow and ice on pavement surfaces.
The most conventional chemical deicing method is salting. Salting can be a cheap and effective method of deicing roads. However, the salt used during these deicing methods can corrode the steel in automobiles and concrete roadway structures cause additional environmental pollution. It has been shown that the use of deicing salts is associated with saline pollution in groundwater and springs in urban areas. Elevated concentrations of salt in groundwater and in roadside areas can damage vegetation and decrease aeration and availability of water in soil. It has also been shown that roadway salting can cause corrosion of steel reinforcements of roadway structures, resulting in both structural damage and a need for costly repairs. For example, degradation of bridge decks has been shown to be particularly pronounced in areas with freezing weather, most notably in the north east and along the Atlantic coast, where only approximately 75% of bridges were still in sound condition after 20 years, as compared to 80% in the Great Lakes and 88% in the lower plains. In another example, it has been estimated that between 1990 and 2000, the cost of repairing bridge decks declared to be unsound ranged between 50 and 200 million dollars a year.
To reduce damage to concrete roadway structures, certain complex chemical solutions have been developed as an alternative to salting. Such complex chemical solutions include potassium acetate, calcium magnesium acetate, calcium magnesium potassium acetate, and the like. Some of these chemical solutions do not contain chloride, and they can be configured to decompose quickly. However, acetate can reduce the durability of asphalt and concrete roadway structures. Also, such complex chemical solutions can be expensive.
Another conventional alternative to chemical deicing methods is the use of thermal technology. Depending on whether the heating source is embedded inside the roadway structure, such thermal deicing systems can be characterized as either internal or external. Internal thermal deicing systems can include hydronic systems, electric heating cable systems, carbon fiber heating wire systems, and the like. External thermal deicing systems can include microwave systems, infrared heating systems, and the like. Such thermal deicing systems can require bulky, power-hungry, and/or unreliable components to enable the heating function. Additionally, such thermal deicing methods can cost significantly more than the conventional chemical deicing methods described above.
Accordingly, a need exists for an environmentally-friendly, safe, efficient, and cost-effective deicing system capable of increasing the operational duration of roadways, particularly during weather events involving snow, ice, and the like. There is a further need for deicing systems that can be constructed using conventional techniques and that comprise a structurally integrated and automated self-heating concrete system that is comparable in cost to conventional roadway salting.